Studies in the Terpenoid Field

Harding, Alexander E (1973) Studies in the Terpenoid Field. PhD thesis, University of Glasgow.

Abstract

This thesis is divided into three sections. Section one concerns an investigation of the liverwort Gymnomitrion obtusum (Lindb) Pears (Hepaticae) which proved to he a rich source of sesquiterpenoids with a novel (5, 3, 1) undecane carton skeleton. Eight new sesquiterpenoids were isolated including the alcohol gymnomitrol, which is the major constituent. The chemical and spectroscopic properties of gymnomitrol and its congeners, which led to the structural elucidation, are described, together with some interesting reactions and more detailed discussions of the mass spectra and lanthanide ion induced shifts in the nuclear magnetic resonance spectra. The absolute configuration of gymnomitrol has been determined by circular dichroism and a plausible biogenesis proposed. The initial stages of a potential synthetic route to this new skeletal type are reported. The discussion of the chemistry of gymnomitrol is prefaced by a brief review of the literature of the Hepaticae. In an extension of the previously reported work on the constituents Elythroxylon monogynun Roxb., which is discussed briefly in the introduction, section two describes the isolation and structural elucidation of seven new diterpenoids from the rootwood of Erythroxylon australe. The structures of these new stachene - and erythroxydiol X - related diterpenoids were assigned on the basis of chemical and spectroscopic evidence and interrelation with known compounds. It is of interest that all the new compounds have an oxygen substituent at C-1. In addition six known diterpenoids were also isolated. In section three the chemistry of some highly complex tetranor-triterpenoids is reviewed. The light petroleum extract of the wood of Trichilia prieuriana (Meliaceae) gave a crystalline substance named prieurianin, which appears to be a member of this group. Despite a considerable amount of data on prieuriariin, including p. m. r. and 13C. m. r. . its structure has still not been established. A suitable derivative for X-ray crystal structure analysis has been prepared and is being examined.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Organic chemistry
• Date of Award: 1973
• Depositing User: Enlighten Team
• Unique ID: glathesis:1973-78631
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 15:07
• Last Modified: 30 Jan 2020 15:07
• URI: https://theses.gla.ac.uk/id/eprint/78631